/* * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * *   - Redistributions of source code must retain the above copyright *     notice, this list of conditions and the following disclaimer. * *   - Redistributions in binary form must reproduce the above copyright *     notice, this list of conditions and the following disclaimer in the *     documentation and/or other materials provided with the distribution. * *   - Neither the name of Sun Microsystems nor the names of its *     contributors may be used to endorse or promote products derived *     from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package events;/* * ComponentEventDemo.java requires no other files. */import javax.swing.*;import java.awt.*;import java.awt.event.*;public class ComponentEventDemo extends JPanel                                implements ComponentListener,                                           ItemListener {    static JFrame frame;    JTextArea display;    JLabel label;    String newline = "\n";    public ComponentEventDemo() {        super(new BorderLayout());        display = new JTextArea();        display.setEditable(false);        JScrollPane scrollPane = new JScrollPane(display);        scrollPane.setPreferredSize(new Dimension(350, 200));        JPanel panel = new JPanel(new BorderLayout());        label = new JLabel("This is a label", JLabel.CENTER);        label.addComponentListener(this);        panel.add(label, BorderLayout.CENTER);        JCheckBox checkbox = new JCheckBox("Label visible", true);        checkbox.addItemListener(this);        checkbox.addComponentListener(this);        panel.add(checkbox, BorderLayout.PAGE_END);        panel.addComponentListener(this);        add(scrollPane, BorderLayout.CENTER);        add(panel, BorderLayout.PAGE_END);        frame.addComponentListener(this);    }    public void itemStateChanged(ItemEvent e) {        if (e.getStateChange() == ItemEvent.SELECTED) {            label.setVisible(true);            //Need to revalidate and repaint, or else the label            //will probably be drawn in the wrong place.            label.revalidate();            label.repaint();        } else {            label.setVisible(false);        }    }    protected void displayMessage(String message) {        //If the text area is not yet realized, and        //we tell it to draw text, it could cause        //a text/AWT tree deadlock. Our solution is        //to ensure that the text area is realized        //before attempting to draw text.       // if (display.isShowing()) {	    display.append(message + newline);            display.setCaretPosition(display.getDocument().getLength());        //}    }    public void componentHidden(ComponentEvent e) {        displayMessage(e.getComponent().getClass().getName() + " --- Hidden");    }    public void componentMoved(ComponentEvent e) {        displayMessage(e.getComponent().getClass().getName() + " --- Moved");    }    public void componentResized(ComponentEvent e) {        displayMessage(e.getComponent().getClass().getName() + " --- Resized ");                }    public void componentShown(ComponentEvent e) {        displayMessage(e.getComponent().getClass().getName() + " --- Shown");    }    /**     * Create the GUI and show it.  For thread safety,     * this method should be invoked from the     * event-dispatching thread.     */    private static void createAndShowGUI() {        //Create and set up the window.        frame = new JFrame("ComponentEventDemo");        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        //Create and set up the content pane.        JComponent newContentPane = new ComponentEventDemo();        newContentPane.setOpaque(true); //content panes must be opaque        frame.setContentPane(newContentPane);        //Display the window.        frame.pack();        frame.setVisible(true);    }    public static void main(String[] args) {        //Schedule a job for the event-dispatching thread:        //creating and showing this application's GUI.        javax.swing.SwingUtilities.invokeLater(new Runnable() {            public void run() {                createAndShowGUI();            }        });    }}